PHYWE Cobra4 Sensor-Unit Conductivity+ Operating Instructions page 3

tion on the measured data recording instrument
The solution to be measured should always be moving a little
during measurement. Keep it in motion by stirring it with a
magnetic stirrer or similar, or by carefully moving the meas-
uring probe to and fro.
If a measuring cell other than the conductivity-temperature
probe Pt1000 (13701.01) is used, then this can be connected
to the Sensor-Unit by means of an adapter for conductivity
measuring cells with DIN plug and 4 mm sockets (13701.02).
The adapter has two 4 mm sockets for connecting conductiv-
ity measuring cells and two 4 mm sockets for connecting
Pt1000 temperature sensors. This assumes, however, that
the conductivity measuring cell and the temperature probe
are each equipped with two 4 mm plugs.
5.3 Cleaning and care of conductivity measuring cells
Conductivity measuring cells do not normally age but,
according to the electrode material, the measurement elec-
trodes could possibly be attacked during measurement in
certain media (e.g. strong acids, and bases) and this could
lead to damage to them. All measuring cells should therefore
be thoroughly rinsed with pure water (demineralized or dis-
tilled) after each usage. Should the measurement electrodes
become contaminated with grease or oil, then the measuring
cell is to be cleaned with warm water and a household clean-
ing agent.
Measuring cells with platinum-clad platinum electrodes, such
as conductivity-temperature probe Pt1000 (13701.01), are
supplied with a protective cap that is filled with distilled water.
These measuring cells must not be allowed to dry out, as it
could then come to a crumbling off platinum black, which
would lead to a change in the cell constant. They must there-
fore always be stored in clean water, e.g. in a protection
sleeve for electrodes, GL 25/12 (37651.15). Do not expose
the measurement electrodes to any mechanical measures
during cleaning of the platinized measuring cell.
5.4 Recording of temperatures
This Sensor-Unit can measure temperature as well as con-
ductivity.
Conductivity-temperature probe Pt1000 (13701.01) has a
Pt1000 temperature sensor integrated in the probe. As the
temperature sensor is inside the measuring head, there is a
short wait until temperature equalization has occurred be-
tween the medium and the temperature sensor, after which
the latter gives the correct temperature of the medium.
Should you want to only measure temperatures, without si-
multaneous recording of the conductivity, then a temperature
sensor with a DIN plug (12123.00), which has a stainless
steel jacket, can be used Because of its construction, this
sensor responds more quickly to temperature changes than
the conductivity-temperature probe Pt1000 (13701.01).
The selection of the measurement channel for temperature
is always made via the Mobile-Link, USB-Link or Wireless-
Link measured value recording instrument.
6 TECHNICAL SPECIFICATIONS
(Typical for 25° C)
Operating temperature range 5... 40° C
Relative humidity < 80%
Conductivity:
The Sensor-Unit has 3 measuring ranges for conductivity.
Selection of a range is made via the instrument connected for
measured value recording:
Measuring range 1
www.phywe.com, © All rights reserved
Resolution
Measurement accuracy± 4% of measured value ± 0.15 µS/cm
Measuring range 2
Resolution
Measurement accuracy
Measuring range 3
Resolution
Measurement accuracy± 4% of measured value ± 0.05 mS/cm
Data rate
Temperature:
Measuring range
Resolution
Measurement accuracy
Data rate
Dimensions:
Housing dimensions (mm)
Weight
7 PARTS SUPPLIED
The extent of delivery is as follows:
Cobra4 Senor-Unit Conductivity+
•
Operating Instructions
•
8 ACCESSORIES
8.1
Conductivity-temperature electrode Pt1000,
DIN plug
Temperature immersion probe Pt1000,
stainless steel, DIN plug
8.2
Adapter for conductivity measuring cells
4 mm socket / DIN plug
Conductivity measuring cell, l = 120 mm,
4 mm plug
Temperature probe Pt1000, glass, 4 mm plug
8.3
cells
The following solution can be used for conductivity measuring
cell calibration:
Calibration solution 1413 µS/cm (25° C), 460 ml
8.4
Protection sleeve for pH electrode, GL 25/12
0.0...2500 µS/cm
± 4% of measured value ± 3 µS/cm
Probes that can be directly connected
Probes needing an adapter for connection
Calibration solution for conductivity measuring
Storage of conductivity measuring cells
0.1 µS/cm
0,0...45000 µS/cm
1 µS/cm
0,0...1000 mS/cm
0.01 mS/cm
1 Hz
-20...+150° C
0,1 K
± 0.5 K
(in the range 0...+100° C)
1 Hz
approx. 60 x 70 x 30
65 g
12632.00
13701.01
12123.00
13701.02
18151.02
13702.01
47070.02
37651.15
3
12632.00 / 4808